Unfortunately, your shelter of opportunity during the zombie apocalypse is a first grade classroom. The good news is that you can have basic illumination. Instructables member Mikeman4290 has a simple solution: tie and tape together three crayons with a string in the middle. This candle should last for an hour.

Science - in the guise of my kid's 3rd grade science fair project - has established that this may have worked in the past but that current crayons from the biggest manufacturers have been formulated to burn poorly if at all. (After the experiments we confirmed this with manufacturers.) Here are two candles made for that experiment - regular candle wax on the left, crayon wax on the right: